Arrangement for securing a press ram to a press plunger



Jan. 28, 1958 F. EBEN El AL ARRANGEMENT FOR SECURING 'A PRESS RAM TO APRESS PLUNGER Filed Jan. 26, 1956 s Sheets-Sheet '1 is 5 a 17 Iwvswrorzs IT'Ebcn,

Jain. 28, 1958 F. EBEN ETAL ARRANGEMENT FOR SECURING A I RESS RAM TO APRESS PLUNGER Filed Jan. 25, 1956 3 Sheeps-Sheet 2 Jan. 28, 1958 F. EBENETAL 2,821,401

I I ARRANGEMENT FOR SECURING A PRESS RAM TO A PRESS PLUNGER Filed Jan.26, 1956 v 3 SheetsSheet 3 Ill 4 I ll mum/W025" F 17 ban, [1110110242141] 3 Q United States Patent ARRANGEMENT FOR SECURING A PRESS RAM TO APRESS PLUNGER Franz Eben, Dusseldorf, Wilhelm Hofmann, Dusseldorf-Oberkassel, and Wilhelm Pirwitz, Ratingen, Germany, assignors toSchloemann Aktiengesellschaft, Dusseldorf, Germany Application January26, 1956, Serial No. 561,569

Claims priority, application Germany February 24, 1955 8 Claims. (Cl.279-1) The insertion and removal of the press ram of presses takes sucha long time, more especially in the case of horizontal presses, that itis found that changing the ram gives rise to a disadvantageous stoppageof work. The object of the invention is to shorten the working timenecessary for changing the ram, and the invention consists primarily inthis, that the (preferably conically shaped) foot of the ram, whichbears against the plunger, has two or more longitudinal groovesco-operating, in the manner of a bayonet joint, with a securing ringadapted to be pressed against the plunger.

So that it will not be necessary to rotate the heavy ram, suspended froma crane, about its longitudinal axis when it is being inserted orremoved, the bayonet joint is so formed that the securing ring isrotatable about the axis of the ram.

Particular reliability of operation is obtained if the securing ring isfreely rotatable on the plunger and is pressed against the foot of theram by a nut adapted to be screwed in on the plunger. To enable thesecuring ring to be rotated, a slot-shaped opening is provided forintroducing a handle by means of which the securing ring can be rotated.

It is particularly advantageous to use a handle which also permits anincrease of force by gearing. This can be done in such a manner that thesecuring ring has external teeth in which pinion teeth engage which areadapted to be moved pivotally by hand or hydraulically. The pinion teethmay be actuated by means of a lever by hand, or else hydraulically, orby means of a magnet or in some other manner.

One embodiment of the invention chosen by way of example is illustratedin the accompanying drawings, in which:

Figure 1 is an axial horizontal section through a press crosshead havinga ram inserted therein, on line IIII of Figure 2,

Figure 2 is a view in elevation, seen in the direction of the arrow I ofFigure 1, and

Figure 3 is a plan view of a press provided with the arrangementaccording to the invention.

Figure 1 shows a press ram 4 secured to a press plunger 1. Both partsare supported by the travelling crosshead 20 of the press. Thetravelling crosshead also slides on tracks 24. The rear end of theplunger 1 slides in a press cylinder 22 and is forced out of the latterin a known manner, oil or water being forced under pressure into thecylinder 22. The withdrawal of the plunger 1, and of the travellingcrosshead 20 which is virtually integral therewith is efiected by meansof pistons not shown in the drawing, which are arranged in the returningcylinders 23 and connected through rods 21 to the travelling crosshead20 to which they are secured by screws. When the plunger 1 is advancedthe ram 4 enters the bore 26 of a container 25 in which there ismaterial for extrusion, for instance heated aluminium. This materialthen passes through a die 28 located in the press head 27, and emerges2,821,401 Patented Jan. 28, 1958 ICC 2 at 29. For limiting the forwardmovement of the plunger 1 and the press ram 4 a stroke limiting ring 19is used which abuts against the container 25 when the ram 4 has gone asfar into the bore 26 as is necessary.

The arrangement described above is known.

A pressure body 2 against which the foot 3 of the press ram 4 bearsforms part of the plunger 1, to which it is secured by means of screws2a. The foot 3 together with a rotatable securing ring 5 forms a bayonetjoint. A nut 6 screwed into a head piece 7, which also forms part of theplunger 1, by means of a thread 8 presses the securing ring 5 andtherefore the foot 3 against the pressure body 2. The head piece 7 isheld by the plunger 1 by means of a plurality of screws 7b of which onlyone is shown in the drawing. On the frusto-conically shaped foot 3 arefour recesses 3a, between which four bearing surfaces 9 are thus left.The securing ring 5 has corresponding recesses 5a, between whichinwardly extending claws 10 are left. The securing, ring, which isrotatably mounted at 11, has on a part of its periphery toothed segments12 in which teeth 13 of a pinion segment 14 engage. The pinion segmentis rockable on a bolt 15 in a slot 7a of the head piece 7 and carries ahand lever 16. For rotating the nut 6 the projecting part of the latteris made polygonal, cf. 6a of Figure 2. A ring 17 formed as a wrench andcapable of being rotated by means of two levers 18 is slid on to thepolygonally shaped part. The levers project through slots 19a of thestroke limiting ring 19. For inserting and extracting the ram,therefore, the latter does not have to be rotated about its axis.

If the ram 4 is to be removed, first of all the nut 6 is loosenedslightly by actuation of the hand levers 18, so that the securing ring 5can be rotated with the aid of the pinion segment 13, the lever 16 beingactuated by hand. After the securing ring has been rotated through 45the ram can be drawn out forwards, i. e. downwards in Figure l, and anew ram in the same angular position can be inserted. For securing theram it is then only necessary to actuate the lever 16 and then thelevers 18.

An advantage gained is that the stroke limiting ring 19 does not have tobe removed when the ram is being changed, and more particularly, thatthe ram can be released from the plunger when it has seized in thecontainer 25. In that case, the ram and the container are both removed,and a new ram and a new container are both inserted, so that the pressis out of operation only for a short time. When rams are secured in theusual manner, the access to the head screws and nuts that have to beloosened is at the end face of the plunger 1, and therefore when thetravelling cross-head 20 and the container 25 are close together acessto said screws and nuts is diflicult or impossible. Therefore, with theknown constructions seizing of the ram in the container always causes asubstantial interruption of work. Obviously, variations from theembodiment chosen by way of example are within the scope of theinvention: thus for instance the securing ring 5 itself may be rotatableby means of a thread in the plunger or in the head piece 7. After thefoot of the ram has ben introduced, said ring is turned, from outside,through a part of one revolution, so that while rotating it is at thesame time displaced longitudinally because of the thread, so that itpresses the foot of the ram against the plunger or the pressure piece.

We claim:

1. Means for detachably securing a press ram to a plane end face on apress plunger, comprising: a rotatable securing ring surrounding thefoot end of the press ram adjacent to the end face of the plunger,inwardly extending radial claws on the securing ring, bearing surfacesextending radially outwards from the foot end of the ram and adapted topass in an axial direction through the recesses between the claws of thesecuring ring and to lodge behind the said claws when the securing ringis turned throiigh a suitable angle, and an abutment member adapted tobe screwed into the end of the plunger and to bear against the securingring, urging it towards the plane end face of the plunger, and therebypressing the end of the ram against the plane end face of the plunger.

2. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 1, the press plunger including ahead-piece formed with an internal screw thread into which the abutmentmember is screwed, and the securing ring being rotatably supportedwithin the head-piece by the abutment member.

3. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 2, further comprising a hand-lever forrotating the securing ring, the head-piece being formed with a slot-likeaperture for the passage of the said hand-lever.

4. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 2, further comprising external teethon the rotatable securing ring, a toothed pinion rotatably mounted inthe head-piece and meshing with the said teeth, and a hand-lever forrotating the said pinion, the head-piece being formed with a slot-likeaperture for the passage of the said hand-lever.

5. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 2, further comprising at least onehand-lever non-rotatably connected with the abutment member, and locatedoutside the head-piece of the plunger.

6. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 5, further comprising astroke-limiting ring mounted on the front of the plunger head-piece,this stroke-limiting ring being formed with at least one slot throughwhich the hand-lever connected with the abutment member extends.

7. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 5, further comprising astroke-limiting ring mounted on the front of the plunger head-piece, thehand-lever connected with the abutment being located outside thisstroke-limiting ring.

8. Means for detachably securing a press ram to a plane end face on apress plunger as claimed in claim 1, the foot of the press ram beingconically widened in the direction towards the plunger, and the claws ofthe securing ring beinginternally conical, so as to bear snugly upon theconical surface of the ram foot.

References Cited in the file of this patent UNITED STATES PATENTS

